Automatic check and shut-off valve



Aug. 29, 1939. J. R. POLSTON 2,171,190

7 AUTOMATIC CHECK AND SHUT-OFF VALVE Filed June so, 1957 2 Sheets-Sheet1 70 22 3 rwe/wbo'b Aug. 29, 1939. J. R. POLSTON 2,171,190

AUTOMATIC CHECK AND SHUT-OFF VALVE Filed June 50, 19s? 2 Sheets-Sheet 2Patented Aug. 29, 1939 UNITED STATES PATIENT oF ica John Ray Polston,Tulsa, Okla. Application June so, 1937, Serial No. 151,201

6 Claims.

This invention relates to valves and more particularly to valvesoperated by fluid pressure.

In the oil industry, producing wells generally have a storage tank orreservoir into which the oil is allowed to accumulate if the pressure ofthe well is sufiiciently high, and into which the oil is pumped if thepressure of the well falls below the necessary values. When the oil hasreached an appropriate depth in the storage reservoirs, the reservoir isconnected to a receiving tank or reservoir. The oil is preferablyallowed to flow by gravity from the storage reservoir into the receivmgreservoir. Where one or more of the storage reservoirs or tanks is lowerthan the receiving tank, it is necessary to use a pump to cause the oilto flow from the storage tank into the receiving tank. Where two or moreof these storage tanks feed into a common gathering line, a so calledtank battery exists. After the pump drawing liquid from low level tanksbuilds up pressure in the gathering lines from higher level tanks, it ispossible that the OH may be pumped from one producer tank into anotherproducer tank instead of into the gathering tank of the pipe linecompany. Where the oil flows by gravity from the storage reservoir intothe receiving tanks or reservoir, and no means are provided forpreventing air from displacing the oil in the pipe-line, after all ofthe oil has flowed out of storage reservoir, then the pipe-line becomesairlocked; which means that air is trapped at high points in thepipe-line and thus retards the flow of oil at the next period that oilis turned into the pipeline. I

It is readily apparent that some means must be provided which will atall times allow the oil to flow from a producing tank and which willprevent a flow of oil from the gathering lines into a producing tank.Furthermore, it is necessary to- 40 prevent a flow of oil from aproducing tank having low relative elevation into other producing tanksof lower relative elevation. It is also very important that thepipe-lines in a gathering system do not become airlocked, especiallythose that depend upon gravity flow.

An object of this invention is to provide means for avoiding theforegoing difliculties.

Another object is to provide an improved automatic valve for eliminatingthe heretofore described difliculties. Another object is to provide animproved valve construction. Further objects include the provision of avalve which will always operate to shut 01f the producer tank from thegathering line whenever the pressure in the gathe e line exceeds t pssure in the producer tank, and also which will close the line wheneverthe pressure in the producing tank decreases below some determinableminimum.

Further objects and advantages of this invention will be readilyunderstood from the follow- 6 ing description taken in connection withthe accompanying drawings.

In the drawings: Figure l is a side elevation ot a-valve includingfeatures of this invention; Figure 2 is a vertical cross section showingthe valve in in open position and corresponding to a section on line 22of Figure 3; Figure 3 is a transverse cross section on line 33 of Figure1; Figure 4 is an elevation similar to Figure 1 showing a slightlymodified operating connection; Figure 5 is is a transverse cross sectionon line 55 of Figure 4 with the valve in seated position; and Figure 6illustrates an application of the improved valves in an oil gatheringsystem.

Considering the drawings in greater detail, the 20 improved valveconstruction is shown in Figures 1, 2 and 3. The valve comprises a mainhousing l0 having inlet and outlet flanges Ii and I2 respectively forsecurement at points i3 to the pipe line. Interiorly of the housing is amain valve seat I 4 and a main valve l5 relatively movable with respectto the seat, and having flanged cupshaped flexible diaphragms l6 and I1positioned in the head l8 of the valve and arranged to move the valvewith respect to its seat. Liquid flowing 30 into the inlet opening 19exerts an upward pressure against the face 20 of diaphragm I6 and'raises the valve l5, allowing liquid to flow from the outlet opening 2iinto the appropriate gathering or gravity line. If the pressure in'the'outlet chamber 22 should exceed that in the inlet chamber 23 pressureacting on the lower face 20 of the diaphragm'lfi will be ineffective toopen the valve because of the application of pressure from the outletchamber 22 upon the upper face of diaphragm II. Under suchcircumstances, the valve will remain seated. If the pressure in chamber22 is less than the pressure in chamber 23, the valve may then openprovided the pressure inchamber 23 is greater than the minimum pressurefor which the valve is allowed to operate. I 7

Considering the valve construction in greater detail, the main housingI0 is divided into outlet and inlet chambers 22 and 23 respectively bypartition walls 25, 26 and 21 and the central portion in which isprovided the valve seat l4. For economy of maintenance, valve seat I4 isremovable or replaceable so that'instead of having to remove the entirevalve structure, it is merely necessary to replace the valve seat whenwear The valve operating mechanism is housed in the upper part of thevalve structure. The body portion and more especially the inlet chamber23 opens upwardly and the housing terminates with the flange 36. Theflanges of the diaphragms l5, I! are outwardly directed at theupper endsof the cup-shaped bodies .of such diaphragms. The

flange of the diaphragm I8 is positioned on the upper face of flange 86and on said plan is positioned the diaphragm spacer ring 31 maintainingthe lower diaphragm IS in spaced relation with respect to the upperdiaphragm ll. The flange of the diaphragm I1 is seated on the ring 31.The valve head or cover I8 is positioned upon the flange of the upperdiaphragm and secured to the flange 38 by means of a series of bolts 38.For the purpose of aligning the parts in proper position, two dowel pinsor rods 39 are provided. These pins pass through aligned openings in thetwo diaphragms and spacer ring and seat in openings 40 and 40a in therespective flanges of the valve housing and valve cover. In this manner,parts will always be aligned in proper position. The diaphragms l6, l1,cover i8 and spacer ring 31 provide a sectional structure which closesthe upper end of chamber 28 and with such structure including upper andlower superimposed compartments, each having its bottom formed by adiaphragm. With reference to the form shown in Figure 3, the lowercompartment communicates with the atmosphere and the upper compartmentcommunicates with the chamber 22. The form shown in Figure 5 disclosesthe upper compartment communicating with the atmosphere and the lowercompartment communicating with the chamber 22.

The upper diaphragm is entirely independent of the lower diaphragm in sofar as mechanism connections are concerned. It will be understood,

however, as hereinafter pointed out, that this diaphragm can cooperatewith the lower diaphragm under appropriate circumstances. The upperdiaphragm is weighted by a weight 42 which is secured centrally by thebolts and nuts 43 and 44, the latter being spaced from the flexiblephragms are arranged in the lower compartner, the hole through thediaphragm willbeeifecttively sealed and the diaphragm will not bedamaged by tightening of the bolts.

The lower diaphragm is also weighted having mounted thereupon theheavier weight 46. The upper surface of the weight 46 is counterbored asat 41 so as to receive the nut 43 without any mechanical interferencebetween the parts. This diaphragm is connected to the main valve ashereinafter described. The weights for the diapphragms are arranged,- inthe lower compartment provided in the sectional structure which closeschamber 23. The weight 42 for the diaphragm I1 is arranged against thelower face of the latter. The weight 48 for the diaphragm i6 is arrangedon the upper face of the latter.

The main valve includes an annular lower part 48 which provides aseating surface 48 airranged to cooperate with the surface 48 of theremovable valve seat l8 for the purpose of closing the latter, Theannular lower part 48 of the main valve provides an outlet therefor. Themain valve is constructed in the form of a cage and it not only includesthe annular lower part 48, but a circular upper part 65 formed. with anaxial opening and having the marginal portion of its lower face rabbetedthroughout and peripherally threaded as at 66, and an annulus 50 whichis connected at its top with the threads 66 and having its bottomintegral with the upper face of the part 48. The annulus 50 is of lessdiameter than the part 48 and is formed with a series of openings 5|which constitute intake ports and through which liquid may flow from theinlet side of thevalve I5. The openings are spaced by the portions 5| ofthe annulus 50. Centrally of the upper face of the lower annular part 48the latter is provided a valve seat 53 for the auxiliary valve 54. Theauxiliary valve 54 is formed on the main valve stem 55 and is movabletherewith. The valve stem 55 is secured in threaded engagement to theweight 46 and in turn locked to the diaphragm i6 by a nut 56 and aninterposed washer 51. This washer similarly seals the opening throughthe diaphragm and prevents the nut from cutting the diaphragm. It willnow be observed, that pressure operating on the lower face of thediaphragm l8 will move the diaphragm in an upward direction and willalso raise the valve stem 55 and the auxiliary valve carried on it. Theauxiliary valve 54 will rise off of its seat and will allow liquid fromthe inlet l9 to flow through the ports 52 in the main valve through thevalve seat 53, the opening 58 of the main valve, and the opening 59 inthe main valve seat and then into the outlet chamber 22. The liquidreaching the outlet 2| will then flow into the gravity line connected toa gathering tank or to the inlet of an appropriate pump, when gravity isinsuillcient to cause the necessary flow of oil. If the pressure in theoutlet chamber 22 exceeds the pressure from the inlet side of the valvethis pressure will be transmitted by means of the pipe 60 to the uppersurface of diaphragm H. Inasmuch as the surfaces of the two diaphragmsare the same, the resulting excess pressure on the upper diaphragm inaddition to the efl'ect of the weights will cause the valve to close. Ifthe inlet pressure falls below that necessary to oppose the action ofthe weights, the valve will also close. If the pressure on the outletside of the valve rises to any appreciable amount, it will force thevalve closed.

If the outlet side of the valve is subjected to a vacuum, the upperdiaphragm l1 and weight 42 will be lifted from its resting position onweight 46. Air from the atmosphere will flll the space between weight 42and weight 46 by means of port 68. Thus no vacuum from outlet side ofvalve will be transmitted to lower diaphragm l6, and therefore weight 46will hold the valve in a closed position unless the liquid pressure oninlet side of valve is sufiicient to lift weight 46. Therefore, thevalve remaining in a closed position during periods of low liquid leveloninlet side of valve and with vacuum on outlet side of valve preventsair or vapor from entering the pipe-line which would eventually cause avapor locked condition in the pipe-line.

To prevent chattering of the valve when a slight difference in pressureoccurs, the lower part 62 of the main valve stem 55 is of reduceddiameter and is slightly smaller than the diam- 2,171,190 eter of thebearing 33. This part of the valve stem acts as a piston riding up anddown in the bearing cylinder and its action is retarded by means 01 thedelayed fluid flow through the port 35, so that these parts cooperate toretard movements of the valve and to provide an action similar to thatof a dash pot.

Oil frequently contains very fine sand which will readily destroy thewalls of the dash pot. To avoid the direct action of the oil upon thevalve stem and the bearing, a truncated sleeve or skirt 63 is attachedto the valve stem by means of a screw 64. The oil flowing through thevalve will not flow directly against the valve stem 62.

The auxiliary valve 54 has limited relative movement with respect to themain valve l5. This movement is limited in the lower direction by thevalve seat 53 and in the upper direction by the circular upper part 65of the valve i5. It will now be appreciated that the auxiliary valve mayopen a limited amount independently of the movement of the main valve.The dash pot and its retarding action controls both valves with respectto their seats so as to avoid chattering. In the arrangement inconnection with Figures 1, 2 and 3, the outlet pressure of the valve isapplied to the upper surface of the diaphragm I! by the pipe connection60 connecting at the lower end by a port 61 into the outlet chamber andby a passage 6| in the head of the valve. In this arrangement, thespacing ring 3'! contains a passage 68 open to the atmosphere. The innersurfaces of the. spacing ring are also bevelled at 69 and ill to preventundue wear on the diaphragms.

In Figures 4 and 5, the structure of the valve is similar to that inFigures 1 to 3 inclusive, but a slightly different operating means isprovided. In this instance, the port 61 in the outlet chamber 22 of thevalve is in communication with the space 1| between the two diaphragmsby a connection 60 to the port 68, In this instance, the space above thediaphragm I! is left in communication with the atmosphere by removingthe plug H from the end of the passage 6|, or by merely leaving thethreaded port 12 open. If the outlet side of the valve is subjected to avacuum, the two diaphragms tend to collapse. Atmospheric pressure on theupper surface of the upper diaphragm and the two weights cooperatingtogether all tend to retain the valve closed. If a pressure aboveatmospheric occurs in the outlet side of the valve, the two diaphragmswill be forced apart and the valve will likewise be retained on itsseat. It will then be apparent that the valve can only open when theinlet pressure exceeds the outlet pressure, or where the outlet pressureis sufiiciently low and the inlet pressure exceeds the load applied bythe weights.

In Figure 6 the system is shown with producer tanks I3, 14 and 15, eachone of which may represent a single tank or a battery of tanks. At theright hand side is a tank 16 corresponding to the gathering orcollecting tank of a pipeline company. This tank feeds the pipe line 11which may go to some distant point such as a refinery, distributingpoint, some storage system, or another pipeline. The tank or tanks 13 isof higher elevation than the tank 16 and by opening the stop valve 18oil will flow by gravity through the automatic valve 19 (of thisinvention) and into the gravity line 80, finally feeding into thegathering line 8| and the gathering tank I6. Whenever the oil level intank 13 falls to such a point that the pressure is less than that in theline 80, the valve 19 will close to prevent a how of'oil from the pipeline 80 back to the tank I3. Furthermore, when the level of liquid inthe tank 13 has dropped to a point where air would enter pipe 82, thevalve again closes to prevent any air from getting into the pipe system.The tanks H and 15 may represent a battery each having its stop valve 18and its respective automatic valve 19 connected to the gathering pipe83. In this instance, if the battery of tanks is lower in level than thegathering tank, then the oil would tend to flow from the gathering tank18 into the battery of tanks. The valve 19 prevents this and a pump 84is provided in the line to feed the oil to the gathering line.

Variations within the scope of this invention are covered by theappended claims.

I claim:

1. A combined check and shut-oil valve in cluding a housing having adual valve structure for automatically controlling the flow through saidhousing, said dual valve structure comprising a main flow opening, amain valve seat in said opening, a floating main valve cooperating withsaid seat, an auxiliary flow opening in said main valve, an auxiliaryvalve seat in said auxiliary flow opening, an auxiliary valvecooperating with said auxiliary valve seat, means operatively connectingsaid auxiliary valve to said main valve, said means permitting limitedindependent movement of said auxiliary valve with respect to said mainvalve, a valve stem fixed to said auxiliary valve, a diaphragm unitoperatively connected to said valve stem, one side of said unit being incommunication with the inlet side of said main valve, whereby so long asthere is an overbalancing pressure on said inlet side, the operation ofsaid valves will be controlled by the inlet pressure, and the other sideof said unit being in direct communication with the outlet side of saidmain valve, whereby a back pressure on said outlet side will maintainsaid valves in closed position.

2. A combined check and shut-off valve as claimed in claim 1 whereinsaid means operatively connecting said auxiliary valve to said mainvalve comprises a cage-like member carried by said main valve andslidably embracing said valve stem.

3. A combined check and shut-off valve as claimed in claim 1 whereinsaid diaphragm unit is weighted to normally close said valves at apressure below a predetermined value on said inlet side.

4. A combined check and shut-off valve including a housing having a dualvalve structure for automatically controlling the flow through saidhousing, said dual valve structure comprising a main flow opening, amain valve seat in said opening, a floating main valve cooperating withsaid seat, an auxiliary flow opening in said main valve, an auxiliaryvalve seat in said auxiliary flow opening, an auxiliary valvecooperating with said auxiliary valve seat, means operatively connectingsaid auxiliary valve to said main valve, said means permitting limitedindependent movement of said auxiliary valve with respect to said mainvalve, a valve stem iixed to said auxiliary valve, a diaphragm unit, apair of spaced independent diaphragms in said unit, one of saiddiaphrag'ms'being connected to said valve stem and responsive topressure conditions on the inlet side of said main valve, whereby solong as there is an overbalancing pressure on said inlet side, theoperation of said valves will be controlled by the inlet pressure,

and the other of said diaphragms being responsive to pressure conditionson the outlet side 01' said main valve, whereby a back pressure on saidoutlet side will maintain said valves in closed position, the areabetween said diaphragms being open to atmosphere.

5. A combined check and shut-oi! valve as claimed in claim 4 wherein atleast one of said diaphragms is weighted to normally close said valvesat a pressure below a predetermined value on said inlet side.

6. An automatic check and shut-oil valve comprising in combination, ahousing having a main valve seat, a weighted main valve relativelymovable with respect to said seat, an auxiliary port in said main valve,a main valve stem having relative movement with respect to said mainvalve. an auxiliary valve bodily carried by said main valve stem andarranged within said main valve, an awciliary valve seat in saidauxiliary port, a diaphragm connected to said main valve stem andoperated in response to pressures on the inlet side of said main valve,said auxiliary valve opening in response to the initial upward movementof said main valve stem and said main valve being opened by saidauxiliary valve in response to the further upward movement of said mainvalve stem, and a diaphragm arranged above said flrst named diaphragmand operated in response to pressure on the outlet side of said mainvalve for shifting said valve stem in a direction to close both theauxiliary valve and the main valve.

. JOHN RAY POLSTON.

